package org.example.NetWork;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
import java.nio.charset.StandardCharsets;

/**
 * @className: UdpEchoServer
 * @author: 芃
 * @description:
 * @date: 2024/5/10 17:55
 */
public class UdpEchoServer {
    private DatagramSocket socket = null;

    public UdpEchoServer(int port) throws SocketException {
        this.socket = new DatagramSocket(port);
    }

    public void start() throws IOException {
        System.out.println("启动服务器!");

        while(true) {
            DatagramPacket requestPacket = new DatagramPacket(new byte[1024], 1024);
            this.socket.receive(requestPacket);
            String request = new String(requestPacket.getData(), 0, requestPacket.getLength(), "UTF-8");
            String response = this.process(request);
            DatagramPacket responsePacket = new DatagramPacket(response.getBytes(StandardCharsets.UTF_8), response.getBytes().length, requestPacket.getSocketAddress());
            System.out.printf("[%s:%d] req: %s, resp: %s\n", requestPacket.getAddress().toString(), requestPacket.getPort(), request, response);
            this.socket.send(responsePacket);
        }
    }

    public String process(String request) {
        return request;
    }

    public static void main(String[] args) throws IOException {
        UdpEchoServer server = new UdpEchoServer(9090);
        server.start();
    }
}
